Today, moving digital infrastructures to cloud computing technologies is no longer a preference but a necessity for operational efficiency and scalability. However, hosting data and applications on third-party cloud providers brings a very important question to the minds of information security managers: "What happens to our ISO 27001 Information Security Management System (ISMS) compliance if we move our data to the cloud, and is our data in the cloud really secure?"
A common misconception is that moving all systems to the cloud completely transfers information security responsibility to the cloud service provider (AWS, Microsoft Azure, Google Cloud, etc.). In reality, the cloud does not eliminate the scope of the ISMS; on the contrary, it changes the risk profile and adds new and more complex security requirements. In this guide, we will cover in detail how to implement ISO 27001 standards in cloud computing environments, the shared responsibility model, and cloud security standards.
The Shared Responsibility Model in the Cloud
The fundamental pillar of cloud security is the "Shared Responsibility Model." This model clearly defines which security controls belong to the cloud service provider (CSP) and which belong to the organization receiving the service (the customer).
In general, the sharing of responsibility is as follows:
- Cloud Provider's Responsibility (Security of the Cloud): The security of physical data centers, server hardware, virtualization layer, and global network infrastructure is the responsibility of the cloud provider.
- Customer's Responsibility (Security in the Cloud): Classification of data hosted on the cloud, user access management (IAM), data encryption, operating system patches, network traffic configuration, and application security are completely the responsibility of the customer.
For example, while preventing the physical theft of the hard drive where your data is hosted is the task of the cloud provider; preventing your data from leaking to the internet due to a weak password or a poorly configured access policy is your responsibility. In ISO 27001 audits, how effectively the controls in these areas under your responsibility are implemented is audited.
ISO 27001 and Cloud Security Standards (ISO 27017 and ISO 27018)
While ISO 27001 provides a general information security framework, two important guideline standards have been developed to address cloud-specific risks and controls in more depth:
ISO/IEC 27017: Information Security Controls for Cloud Services
Defines specific security controls for cloud environments in addition to the Annex A controls of ISO 27001. It is a guide for both cloud providers and cloud customers. It covers clarifying shared responsibilities, isolating virtual machines, change management in cloud environments, and incident response processes.
ISO/IEC 27018: Protection of Personally Identifiable Information (PII) in Public Clouds
Focuses on the security of personal data processed in the cloud environment (within the scope of KVKK and GDPR). It includes strict rules such as cross-border data transfer, data minimization, transparency, and not using customer data for advertising purposes.
Integrating the controls offered by these two auxiliary standards into ISMS processes provides a great advantage for an organization using cloud infrastructure to successfully pass ISO 27001 audits.
Evaluation and Selection of Cloud Providers
The ISO 27001 standard requires the management of security risks of outsourced service providers (suppliers). When choosing a cloud provider, you should carefully evaluate the following elements:
- Security Certificates: Verify whether the provider you choose has international security certificates such as ISO 27001, ISO 27017, ISO 27018, and SOC 2.
- Data Residency: Learn in which countries' data centers your data is physically stored. Especially in terms of KVKK (Personal Data Protection Law) compliance, attention should be paid to the rules of transferring personal data abroad. Providers that offer data storage options in Turkey or within EU borders should be preferred.
- Service Level Agreements (SLA): Review commitments regarding data availability, backup frequency, and disaster recovery scenarios.
Corporate Cloud Security Management
An integrated security approach is required for all organizations, especially technopark companies, public contractors, and SMEs in Ankara, that want to protect their cloud infrastructure against cyber threats and ensure ISO 27001 compliance. With the proactive Managed Services we offer as LeonX, we ensure that your cloud infrastructure remains secure at all times.
To tighten identity controls in cloud environments, prevent data leaks, and manage legal compliance processes completely, you can benefit from our Cloud Security and Compliance Management solutions offered by our expert team.
Additionally, you can review our other important guides to support your cloud security infrastructure and ISO 27001 compliance process:
- For identity and access controls in cloud environments: ISO 27001 Access Control
- To analyze risks in your system: ISO 27001 Risk Assessment
- To draw your ISMS scope boundaries: ISO 27001 Scope Definition
- For security of the cloud network infrastructure: ISO 27001 and Network Security
- For cloud backup strategies: The Role of Backup Policies
- To prepare for internal audit processes: ISO 27001 Internal Audit
- To prepare for auditors' questions: ISO 27001 Audit Questions
- For all benefits that certification provides to the organization: ISO 27001 Certification Benefits
- For cyber incident response processes: ISO 27001 and Cybersecurity Incidents
- To learn about the general structure of the standard: What is ISO 27001?
To make your cloud architecture compliant with ISO 27001 standards, perform your risk analyses, and create a secure cloud migration strategy, please contact us at any time.
Frequently Asked Questions
Does our cloud provider having an ISO 27001 certificate mean we are also certified?
Absolutely no. Your cloud provider's certificate only covers the infrastructure under its own responsibility (physical data centers, hardware, etc.). Your applications running on the cloud, the data you store, your access policies, and your managerial processes are evaluated separately by auditors. It is mandatory to document your own processes to obtain your own ISMS certificate.
How is the ISO 27001 scope determined in hybrid cloud architectures?
In hybrid cloud architectures, the scope should include both your on-premise infrastructure and the cloud services you use. When performing a risk assessment, data transfer processes from local servers to the cloud, connection security in between (VPN, MPLS, etc.), and access controls in both environments should be handled in an integrated manner.
Is encrypting our data in the cloud mandatory for ISO 27001?
The ISO 27001 standard does not specify encryption as an "absolute requirement" directly; however, it treats it as a control to be implemented based on the risk assessment result. Encrypting data both in-transit and at-rest in cloud environments is considered one of the most fundamental requirements by auditors as it minimizes data leak risks.
Conclusion
While cloud computing brings immense flexibility and speed to organizations, it does not eliminate information security responsibilities. Establishing an ISO 27001 compliant cloud infrastructure goes through understanding the shared responsibility model correctly, implementing strong access controls, and auditing cloud providers according to strict cybersecurity criteria. A correctly structured cloud security strategy protects your corporate data at the highest level while allowing you to complete your digital transformation securely.
